As the “paperless office” has moved forward and produced a frequently occurring situation whereby documents are no longer available or no longer exclusively available in printed form but are in the form of electronic data, for which documents a legal retention period of 30 years or longer applies in the business and even in the private sphere, an ever-increasing need has arisen for the ability to provide legally secure archiving of the accumulating data. The problems of long-term storage of have grown along with the exponential growth of electronic information, despite the fact that software technologies are fundamentally better suited for managing information than is possible by traditional means with paper and file folders. Since documents in electronic form can be easily modified, measures must be taken to ensure that the archived data remain in their original state. Electronic signatures enable electronic documents to obtain the same legal character as manually signed documents.
Legislators have attached strict requirements to the fact that such documents must constitute court-admissible evidence. German legislators have implemented directive 1999/93/EC (“Electronic Signature Directive”) of the European Union, which governs the use of electronic signatures, through the Electronic Signature Act (SigG) and the Electronic Signature Ordinance (SigV). These state that an electronic document provided with a qualified electronic signature has the same status as it does in written form. The qualified electronic signature to the greatest extend possible has the same legal validity as the handwritten signature. As a result, documents signed in this way, such as for example e-mails or electronic invoices, can be used as evidence in court in the same way as their counterparts on paper. When files are archived, the signature files can either be stored separately from the original file or attached to this file.
Electronic long-term archiving refers to preservation of electronic information over a period longer than ten years. To this end, archive systems have been developed that are composed of databases, archive software, and storage systems. These systems are based on the approach whereby a reference database including the management and indexing criteria links to an external storage medium to which the data are relocated. This enables a large quantity of information to be relocated to separate archive storage media.
Conventional electronic archives entail the disadvantage, however, that search procedures have been provided in extremely cumbersome form for finding individual archive data or filtering the data according to special criteria, specially whenever a very large quantity of (small) archive data is involved. In addition, these archive data can eventually occupy a large amount of storage space, with the result that it is desirable to reduce storage space while maintaining a qualified electronic signature so that the documents can continue to function as court-admissible evidence. In addition, it is advantageous if the data can be reconstituted with bit-level precision when they are reconstructed.